| Computer Code: |
FH |
Preferred Map Code: |
notEntered |
| Status Code: |
Pending Upgrade |
| Age range: |
Marine Isotope Stage 2 (QMIS002)
— Marine Isotope Stage 1 (QMIS001) |
| Lithological Description: |
Varies from muds and silty muds to sands and gravelly sands. The former muddy lithologies tend to occur mainly in the lower part of the sequence. NOTE: In this area (56 deg north, 3 deg west + 56 deg north, 4 deg west) it has been possible to subdivide the formation into two members. Unfortunately, although this unit can be extended over a wide area of the west central North Sea, it has not been possible to subdivide the unit elsewhere without present knowledge. |
| Definition of Lower Boundary: |
In the Tay-Forth area (1:250,000 Sheet 56 deg. north, 4 deg. west) the Forth Formation generally rests unconformably on the St Abbs/Wee Bankie Formations or rockhead. Locally it may rest conformably on the St Abbs Formation. Further east in the Marr Bank/Devil's Hole areas (56 deg. north, 2 deg. west, + 56 deg.) the unit may form an infill to deep erosive channels hence resting unconformably on the pre-existing sediments. |
| Definition of Upper Boundary: |
Top of unit is unconformably overlain by seabed sediments. |
| Thickness: |
Varies from < 5 metres - 60 metres. |
| Geographical Limits: |
Not defined. |
| Parent Unit: |
Reaper Glacigenic Group (REAP)
|
| Previous Name(s): |
Forth Beds [Obsolete Name and Code: Use FH]
(-2800)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| none recorded or not applicable |
| Reference(s): |
| Thomson, M E, and Eden, R A. 1977. Quaternary deposits of the central North Sea, 3. The Quaternary sequence in the west-central North Sea. Report of the Institute of Geological Sciences, No. 77/12. |
| Stoker, M S, Balson, P S, Long, D, and Tappin, D R. 2011. An overview of the lithostratigraphical framework for the Quaternary deposits on the United Kingdom continental shelf. British Geological Survey Research Report, RR/11/03. 48pp. |
| Stoker, M S, Long, D, and Fyfe, J A. 1985. A revised Quaternary stratigraphy for the central North Sea. Report of the British Geological Survey, Vol. 17, No. 2. |
| Gatliff, R W, Richards, P C, Smith, K, Graham, C C, McCormac, M, Smith, N J P, Long, D, Cameron, T D J, Evans, D, Stevenson, A G, Bulat, J, and Ritchie, J D. 1994. United Kingdom offshore regional report: the geology of the central North Sea. (London: HMSO for the British Geological Survey.) |
| Cameron, T D J, and Holmes, R. 1999. The Continental Shelf. 125-139 in A revised correlation of Quaternary deposits in the British Isles. Bowen, D Q (editor). Special Report of the Geological Society of London, No. 23. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
